Comparison of ASRock Radeon RX 6700 XT Challenger D 12GB video card vs Sapphire Radeon RX 6600 video card by specifications and benchmarks. ASRock Radeon RX 6700 XT Challenger D 12GB runs at 2.321 GHz base clock speed and has 12 GB of GDDR6 memory, while video card Sapphire Radeon RX 6600 runs at 1.626 GHz base clock speed and has 8 GB of GDDR6 memory. The TDP of the first video card is 230 W, and the second is 132 W. Compare the table of benchmark results to find out which graphic card is better.